Welding electrode holder



WELDING ELECTRODE HOLDER April 6, 1943. E. F. HOLT I Filed March 28, 1942 7 Ill/10$ III M INVENTOR. K fldman F1101? 72mg; $44M;

ATTORNEYS Patented Apr. 6, .1943

WELDING ELECTRODE nomma Edman Francis Holt, Indianapolis, Ind., acsignor to P. R. Mallory 8a 00., a corporation of Delaware I Application-March 2a, 1942, Serial No. 436,692

(Cl. 21a-4) 4 Claims.

This invention relates to welding electrode holders and the cooling means therefor.

An object of the invention is to improve electrode holders and the arrangements for cooling weldingelectrodes.

Other objects of the'invention will be apparent from the following description and accompanying drawing taken in connection with the appended claims.

, The invention comprises the features of construction, combination of elements, arrangement of parts, and methods of manufacture and operation referred to above or which will be brought out and exemplified in the disclosure hereinafter set forth, including the illustrations in the drawmg.

In the drawing:

Figure 1 is a side view partly in section of a welding electrodeholder, an adapter therefor and 8. welding electrode supported thereby; and Figure 2 is a side view of the adapter.

In certain resistance welding operations such as the spot welding of aluminum and aluminum alloys, it has been found desirable to operate the welding electrodes at a substantially reduced temperature lower than that obtained. with con ventional water cooling. If the pressure exerting tips of the welding electrodes are maintained at a sumciently low temperature it has been found that the tips have much less tendency to spread out or "mushroom and less tendency to pick up metal from the work being welded. The electrical conductivity of the increased substantially, when high conductivity metals such as aluminum are being welded. a

While it is desirable for greatest strength and electrode is also thereby electrical conductivity that the entire electrode supporting structure be kept reasonably cool, the improvement resulting from cooling is most marked at the pressure exertingtip of the elecan important factor' 1110., Indianapolis, Ind.,

electrode adapter element is attached to the end of a standard water cooled electrode holder and .is provided with conduits for conveying refrigerant fluid through the adapter. Heat insulating means may also be provided between the adapter and the electrode holder to reduce the rate of heat transfer therebetween and help to concentrate the refrigerating effect at the welding electrode. The holder and part of the welding arm are thereby maintained .at a temperature sufficiently low to retain their high strength and electrical conductivity while the welding elec' trode is super-cooled to a much lower temperature in a highly eflicientmanner. v

Referring to the drawing the welding. electrode I0 having a water cooling recess therein is fitt'ed within tapered socket I8 of an electrode adapter member II. The adapter II, illustrated separately in Figure 2, comprises a hollow tubular body closed at the upper end and having hose connecting nipples and 22 screwed into the body thereof to convey refrigerant fluid such as refrigerated brine solution from supply hose I! through the adapter to return hose 23. A short tube 2| axially located within'the adapter serves to convey the refrigerant into the hollow of the welding electrode.

The closed upper end of adapter I I is providedwith a tapered plug connector I! adapted to be fitted within the tapered recess at the lower end of water cooled electrode I2. Holder I2 coinprises a hollow tubular shank which is clamped at the end of arm I3 of the welding machine and has cooling water supply and return hoses I4 connected to it at its upper end. The water supply hose is attached toa small-tube I5 mounted within the bore of holder I 2 to carry the cooling water to the lower end of the holder. A

trode which comes in contact with the work being welded. It is, therefore, desirable to concentratethe greatest cooling effect possible at the welding If a refrigerant is circulated through a conventional welding electrode holder which is clampcd in the welding arm of the machine a great deal of the cooling efiect is dissipated toward the upper end of the holder and through the welding arm of the machine so as to considerably reduce the degree of cooling obtained at the welding tip and reduce efficiency of the result obtained with the refrigerating system ,used.

According to the present invention, a hollow plug I6 of insulating material such as cork, is fitted within the tapered recess at the lower end of holder I2 to produce a certain amount of thermal insulation between adapter II and holder I2 so that the adapter may be operated at a temperature substantially lower than that of the cooling water in the holder.

In operation, the holder I2 may be supplied with cooling water in the usual manner such as water having a temperature of about 20 C. The adapter I I is supplied with refrigerated brine solution at a much lower temperature such as --30 or --40 C., or even lower. According to an alternative mode of operation, the outlet tube 23 leading from the adapter may be connected by an adjustable 3 way valve with the inlet tube I4 for the electrode holder so that a portion of the brine chanical strength and conductivity of the holder and welding arm.

It is also contemplated that in some instances, by using high pressure tubing for hoses l9 and 23, the adapter I I may be made part of the fluid expansion passages of a compressor or absorption type refrigerating system using ammonia gas, Freon or the other similar refrigerant.

It will be obvious that threaded male or female connections may be used instead of the tapered connections shown between the adapter and the electrode and the electrode holder.

While the present invention, as to its objects and advantages, has been described herein as carried out in specific embodiments thereof, it is not desired to be limited thereby but it is intended to cover the invention broadly within the spirit and scope of the appended claims.

What is claimed is:

l. A pressure exerting welding electrode support comprising, in combination, a hollow tubular holder adapted to be clamped to the arm of a welding machine and conduits leading to and from said holder for circulating cooling fluid therethrough, a hollow adapter supported on the end of said holder and conductively in contact therewith and conduits leading to and from said adapter for circulating cooling fluid therethrough independently of circulation through said holder, said adapter having an electrode supporting .portion formed therein to receive a welding electrode in current and heat conducting contact'therewith,- and thermal insulating material between the hollow portion of said holder and said adapter to retard heat flow therebetween.

2. A welding electrode adapter for supporting a welding electrode in a welding electrode holder whereby said holder and adapter may be sepacomprising a hollow tubular body having a closed end and an open end, the closed end thereof being tapered to flt a tapered socket in a holder. the open end being formed witha tapered socket for receiving the tapered shank of a welding electrode, and fluid inlet and outlet tubes leading into and out of the hollow portion of said adapter through the tubular body wall thereof.

3. A welding electrode adapter for supporting a welding electrode in a'welding electrode hol'der comprising a hollow tubular body having a closed end and an open end, said closed end being tapered to fit a tapered socket, said open end having a tapered socket to receive a tapered welding electrode shank and fluid inlet and outlet tubes attached to the body of said adapter and communicating with the hollow interior thereof.

4. A pressure exerting welding electrode support-compising, in combination, a hollow tubular metal holder adapted to be clamped to the arm of a welding machine and conduits leading to and from said holder for circulating cooling fluid therethrough, the hollow in said holder extending to one end thereof and terminating in a tapered socket, a hollow tubular adapter having a closed and an open end with the closed end tapered and held in said tapered socket, the open end of said adapter terminating in a tapered socket for receiving a welding electrode, and fluid inlet and outlet tubes leading into and out of the hollow portion of said adapter through the tubular body wall thereof, and a plug of thermal insulating material in the smaller end of the tapered socket in said holder to retard heat flow between said adapter and any cooling fluid in said holder,

rately and independently cooled by cooling fluids operating at different temperatures. v I EDMAN FRANCIS Horn. 

